Method and system for reducing PIM protocol DR change

Abstract

A method and system for reducing changes in a designated router (DR) of a protocol independent multicast (PIM) protocol are disclosed. The method includes: after a PIM device joins a shared network, an interface of the PIM device receiving a Hello message sent by other PIM device in the shared network, wherein the Hello message carries a DR address option; and the interface of the PIM device using a currently used DR address carried in the Hello message as a DR address of the interface.

What we claim is: 
     
       1. A method for reducing changes in a designated router, DR, of a protocol independent multicast, PIM, protocol, comprising the following steps:
 after a PIM device joins a shared network, receiving, by an interface of the PIM device, a Hello message sent by other PIM device in the shared network, wherein the Hello message carries a DR address option; and 
 using, by the interface of the PIM device, a currently used DR address carried in the Hello message as a DR address of the interface. 
 
     
     
       2. The method for reducing changes in a DR of a PIM protocol according to  claim 1 , further comprising: after the PIM device joins the shared network, and before the interface of the PIM device receives the Hello message sent by other PIM device in the shared network, entering, by the interface of the PIM device, a wait state and starting a wait state timer, and sending, by the PIM device, a Hello message carrying the DR address option. 
     
     
       3. The method for reducing changes in a DR of a PIM protocol according to  claim 2 , wherein in the DR address option carried in the Hello message sent by the PIM device, a DR address is 0 or empty. 
     
     
       4. The method for reducing changes in a DR of a PIM protocol according to  claim 2 , further comprising: after the wait state timer of the interface of the PIM device times out, or after the interface of the PIM device receives a Hello message which carries the DR address option and in which a DR address is a legal unicast address, ending the wait state of the interface of the PIM device and entering a DR election state. 
     
     
       5. The method for reducing changes in a DR of a PIM protocol according to  claim 4 , wherein after the wait state timer of the interface of the PIM device times out, the interface of the PIM device elects a new DR and sends a Hello message carrying an address of the newest DR. 
     
     
       6. The method for reducing changes in a DR of a PIM protocol according to  claim 1 , wherein the using, by the interface of the PIM device, a currently used DR address carried in the Hello message as a DR address of the interface comprises: after the interface of the PIM device receives a Hello message which carries the DR address option and in which a DR address is a legal unicast address, using, by the interface of the PIM device, the DR address carried by the received Hello message as the DR address of the interface. 
     
     
       7. A system for reducing changes in a designated router, DR, of a protocol independent multicast, PIM, protocol, provided in a PIM device and comprising a processor and a storage device, wherein the storage device stores processor-executable programs, and the processor-executable programs comprise a message transceiving module and a protocol processing module, wherein
 the message transceiving module is configured to, after the PIM device joins a shared network, receive a Hello message sent by other PIM device in the shared network, wherein the Hello message carries a DR address option; and 
 the protocol processing module is configured to use a currently used DR address carried in the Hello message as a DR address of an interface of the PIM device. 
 
     
     
       8. The system for reducing changes in a DR of a PIM protocol according to  claim 7 , the processor-executable programs further comprise a state management module configured to, after the PIM device joins the shared network, make the interface of the PIM device enter a wait state, start a wait state timer, and notify the message transceiving module to send a Hello message which carries the DR address option and in which a DR address is 0 or empty. 
     
     
       9. The system for reducing changes in a DR of a PIM protocol according to  claim 8 , wherein the state management module is further configured to, after the wait state timer of the interface of the PIM device times out, or after the message transceiving module receives a Hello message which carries the DR address option and in which a DR address is a legal unicast address, end the wait state of the interface of the PIM device and enter a DR election state. 
     
     
       10. The system for reducing changes in a DR of a PIM protocol according to  claim 9 , wherein the protocol processing module is further configured to, after the wait state timer of the interface of the PIM device times out, elect a new DR and notify the message transceiving module to send a Hello message carrying an address of the newest DR. 
     
     
       11. The system for reducing changes in a DR of a PIM protocol according to  claim 9 , wherein the protocol processing module using the currently used DR address carried in the Hello message as the DR address of the interface of the PIM device comprises that the protocol processing module is configured to, after the message transceiving module receives the Hello message which carries the DR address option and in which the DR address is the legal unicast address, use the DR address carried in the received Hello message as the DR address of the interface of the PIM device. 
     
     
       12. A non-transitory computer readable storage medium having program instructions stored therein, which, when executed, can implement the method for reducing changes in the DR of the PIM protocol according to  claim 1 . 
     
     
       13. A non-transitory computer readable storage medium having program instructions stored therein, which, when executed, can implement the method for reducing changes in the DR of the PIM protocol according to  claim 2 . 
     
     
       14. A non-transitory computer readable storage medium having program instructions stored therein, which, when executed, can implement the method for reducing changes in the DR of the PIM protocol according to  claim 3 . 
     
     
       15. A non-transitory computer readable storage medium having program instructions stored therein, which, when executed, can implement the method for reducing changes in the DR of the PIM protocol according to  claim 4 . 
     
     
       16. A non-transitory computer readable storage medium having program instructions stored therein, which, when executed, can implement the method for reducing changes in the DR of the PIM protocol according to  claim 5 . 
     
     
       17. A non-transitory computer readable storage medium having program instructions stored therein, which, when executed, can implement the method for reducing changes in the DR of the PIM protocol according to  claim 6 .